1. Field of the Invention
The present invention relates to a system, such as a laptop type portable computer or a laptop type wordprocessor, wherein a flat panel display unit is connected to a main body and, more particularly, to a system wherein a flat panel display unit can be detached from a main body.
2. Description of the Related Art
In recent years, laptop type portable computers having main bodies to which large-size flat panel display units are rotatably connected have been widely used. These laptop type portable computers are disclosed in, e.g., U.S. Pat. Nos. 4,497,036, 4,571,456, 4,667,299, 4,730,364, 4,739,316, 4,742,478, 4,749,364, 4,781,422, 4,839,837, 4,846,536, 4,852,033, 4,684,523, 4,894,792, 4,901,261, and 4,903,221.
Of these laptop type portable computers, display detachable type portable computers disclosed in, e.g., U.S. Pat. No. 4,749,364, U.S. patent application Ser. Nos. 07/428,772, and 07/406,614 have flat panel display units detachable from computer main bodies. A display detachable type portable computer of this type is used in the following two types of operation modes. In the first operation mode, a flat panel display unit is electrically and mechanically connected to a computer main body. In the second operation mode, the flat panel display unit is detached from the computer main body, and the computer main body is electrically connected to a CRT display unit. An operator normally operates the display detachable type portable computer in the first operation mode. Since currently available flat panel displays have low resolutions, when an operator wants to see high-resolution images, he/she electrically connects a computer body to a CRT display unit. When the operator uses the computer main body by connecting it to the CRT display unit, he/she detaches the flat panel display unit from the computer main body because it interferes with this type of operation. In this case, therefore, the operator operates the computer main body without the flat panel display unit.
Although the flat panel display unit can be detached from the main body of the above-described display detachable type portable computer, a flat panel display unit to be mounted on one type of portable computer is limited to only one type. Various types of flat panel displays are currently available, e.g., a reflection type liquid crystal display for reflecting external light, a transmission type liquid crystal display for receiving light from the rear surface, a color liquid crystal display, and a plasma display. In spite of these various types of displays, a user can use only one type of flat panel display for one type of display detachable type portable computer because the physical and electrical specifications of a computer body are matched with only one type of display.